## Chemistry: The Molecular Science (5th Edition)

$0.10M$ $KCN$ is more basic.
** You can find the $K_b$ values on table: 14.2 (Page 624) Since both solutions have the same concentration, we just have to determine which compound is more basic: -$NH_3$: $NH_3$ is a base with $K_b = 1.8 \times 10^{-5}$ - $KCN$: It is a salt formed by $K^+$ and $CN^-$. $K^+$ has negligible acidity, so, we don't need to consider it. $CN^-$ is a base with $K_b = 3.0 \times 10^{-5}$ $CN^-$ has a greater $K_b$ value, therefore, it is more basic. So, $0.10M$ $KCN$ is more basic.